Mailboxes of the "rural" type are fastened on the top or side of a post which suspends the container at a vehicle window level position beside the street. The mail carrier drives into position beside the box, opens the box door, deposits the mail in the box from the front, closes the box door and drives to the next mailbox. If the resident has placed outgoing mail in the box prior to the time that the mail carrier arrives, the mail carrier takes out the outgoing mail before placing the incoming mail in the box.
Because the function of the rural mailbox has a significant effect on the operation of the letter carrier, and the efficiency of the pickup and delivery operation at the mailbox site, the United States Postal Service Government Agency prescribes many of the features of the construction of the rural mailbox by means of rules and regulations. Consequently there is a substantial amount of uniformity in construction of rural mailboxes although there are a variety of manufacturers and different styles available, and in use.
Among the prescribed features is that the front door must be hinged at the bottom and opened downward. Another requirement is that the mailbox be provided with a movable flag on the right side, usually in the form of a metal pendant shaped member.
This flag is for the purpose indicating to mail carrier that the resident has placed "out-going" mail in the box that the resident wishes to be taken by the mail carrier to the post office. The indication is given by the resident, who raises the flag to a vertical position at the time that the outgoing mail is placed in the box. By this means the mail carrier will know that he or she should stop even though there is not any "incoming" mail to put in the box. The regulations provide for the type of hasp on the front door and the means of mounting, etc.
The regulations do not prescribe nor recognize a common problem in the use of rural mailboxes which users have known for many years. Although the flag provides a means to signal to the mail carrier that there is mail to be picked up, the resident receives no signal that mail has been deposited in the box. Therefore, the common practice is to either watch for the mail carrier from the residence and/or come out from the residence to the mailbox to look in and see if there is any incoming mail. This process of "checking" the mailbox is inconvenient, time and energy consuming, and inclement weather may even be unhealthy.
Therefore, there has been a recognized need for a mailbox having a provision to indicate to the resident that the mail carrier has been to the box and opened the box with a presumption that incoming mail has been placed in the box. This "mails-in" signal has been provided in various ways of the prior art.
Numerous inventions have been made and patented in the field of rural mailboxes. Some of these have been directed to solving the problem of providing an indication that the box has been opened by the mail carrier and that there may be incoming mail in the box.
U.S. Pat. No. 4,437,607 Negosta shows a rural mailbox having a window in an enclosure on the back of the box. The window changes color when activated by release of a spring biased rod within the box. The rod presses against the door in the closed position and is relieved by the opening of the front door. The signal panel rotates into position in the window on the back of the box when the rod disengages from the panel.
U.S. Pat. No. 4,318,507 Thopsey et al. reveals a mail arrival flag system in which an external flag on the rear of the box rotates to a vertical position under influence of a counter weight when released by a wire that is activated by the opening of the front door. The wire is fastened to the door and pulled out of engagement with the signal element when the door is opened. When the signal element has been activated it is in a vertical position.
U.S. Pat. No. 3,606,141 Taylor shows a rotary signaling vane which is housed in a transport enclosure. When activated by the opening of the front door on the mailbox the vane turns from the askew "cocked" position to a vertical position in the transparent window under the influence of a weight on an arm of the vane member.
U.S. Pat. No. 3,194,491 Parker reveals a mailbox with a signaling device in which a signal element rotates 180.degree. under the influence of a counter weight when a rod in the upper portion of the mailbox is released by the opening of the front door. The signal element has a flag portion which is transverse to the back of the box and a second signal element which is parallel to the back of the box when the signal element rotates 180.degree. these signal elements change from the upper position to the lower position or vice versa and the change in position is recognizable from the side view and from rear view.
U.S. Pat. No. 3,026,025 Hanson is an earlier patent showing a rotary signal element on the back of a mailbox which falls in rotation from an upper cocked position to a lower released position when released by a rod that moves transversely in the upper area inside the box.
One primary disadvantage of the patents in the prior art which have been directed to the feature of providing a signal when the "mails-in", i.e. the box has been opened, is that the signal elements are positioned in substantially a vertical position and within the plane of the sides of the box in the released and positive indication position. With the signal element in this position it is invisible when the mailbox is mounted in any way where there is an obstruction to the view of the rear of the box. If the mailbox post sticks up above the top of the mailbox in the mounted position (or if the mailbox is mounted on a wall that sticks up above the box) the signal can not be seen because it is hidden from view. Since many mailboxes are mounted in one of these positions such prior art mailboxes are limited in their use. The number of mountings with the back of the box hidden is not infrequent.
In addition, many prior mailboxes having a "mails in" feature are very complicated in construction, requiring a large number of extra parts for the mailbox and extra operations in the assembly procedures. Many of these prior art boxes have operating positions inside the box that interfere with the mail.